At least 15 leftist rebels have been killed in clashes with Colombian troops.

Colombian officials said Sunday most of those killed were members of the Revolutionary Armed Forces of Colombia (FARC).

The fighting came two days after FARC forces attacked two towns, killing three police officers and a girl.

For more than 40 years, Colombia has been mired in a civil war involving the 12,000 strong FARC and a smaller rebel group, rightist paramilitaries and the government. The conflict leaves thousands of people dead each year.